Abstract:

This thesis comprises two parts. In part I (chapters 2 - 6) the activated sludge processfundamentals, modifications, process kinetics and its capabilities are discussed. In addition domestic, textile and tannery waste water characteristics and their effects on activated sludge treatment, alone or when they are combined, is briefly presented. Besides consideration is given on managerial and economic aspect of combined treatment. Part II (chapters 7 - 11) is an original work of the author on combined treatment of tannery and/or textile waste waters with domestic sewage in an activated sludge model. Four tests were conducted. Domestic sewage alone, textile and domestic, tannery and domestic and textile, tannery and domestic. Upto 30 % of the industrial waste waters were mixed with domestic sewage in the two cases while when all were mixed 60% industrial to 40 % domestic sewage was reached. In all cases, up to the proportion described, good substrate removal and complete nitrification were obtained. Some problems, like poor settleability, were encountered during the experiment. These are dealt in the text. However, these problems did not so much affect the performance of the process and good results were still obtained. Finally few oxygen uptake rate tests made for toxicity and inhibition indicated that both waste waters can sometimes betoxic and some times not depending on their strength. Still, up to 30 % both were found to be non-toxic for any strength. /Kir09